"Phablets", the large-screened phones with screen sizes of between 5in and 7in diagonally, sold as well as tablets and laptops combined in the Asia-Pacific region during the second quarter, says research company IDC.

The news indicates that the smartphone business has created a new category lying between the standard smartphone and the tablet, first mapped out by Dell with its Streak phone in June 2010, but subsequently capitalised on by Samsung with its Galaxy Note and successors.

Phablet shipments have grown dramatically - doubling between the first and second quarter, and rising sixfold compared to the same time last year.

However Samsung's principal rival in the smartphone space, Apple, is unlikely to be able to capitalise on the popularity of phablets this year. Its new iPhones, expected to be unveiled this month, will be using the same 4in screen seen in last year's iPhone 5, according to leaks from the supply chain over the past few months. That suggests that it would not be able to introduce a "phablet"-style device before 2014 - even if it wants to.

Analysts had foreseen the potential for 2013 to be "the year of the phablet" in January, after noting the rapid rise of the large-screened phones in 2012. That month saw China's Huawei and ZTE both launch their own versions at the Consumer Electronics Show. Taiwan's HTC has also followed with its own "Butterfly" model.

Samsung more recently staked out the top end of the phablet space with its 6.3in Galaxy Mega, unveiled in April.

"Users have realised that a nearly 5-inch screen isn't such a cumbersome device," said Joshua Flood of ABI Research in January, and forecast then that countries such as Japan and South Korea, and then India, China and Malaysia, would be major markets for the larger devices.

Neil Mawston of Strategy Analytics was more straightforward: "We expect 2013 to be the year of the phablet," he said in January.

Flood's forecast has been borne out, with phablets accounting for 30% of all smartphone sales in India.

The key beneficiary is Samsung, whose Galaxy Note range - due to be enhanced this week with the Note 3 on Wednesday - had nearly 50% of the market.

But it has had to fight off rivals which have jumped onto the bandwagon. At its launch at the end of 2011, the Note had 90% of the much smaller phablet space.

Their popularity points to a regional preference for larger screens which can be used to carry out work on the go, rather than separate functions to a smaller smartphone and larger tablet.

The Asia/Pacific region, and especially China, are seen as a key battleground for the smartphone business as western markets such as North America and Europe move past the early burst of adoption, and sales growth there slows down. By contrast countries such as China, India and others are seeing rapid uptake.

"Phablets first started as a trend driven by mature markets like South Korea, Hong Kong and Singapore – and these markets continue to rise," said Melissa Chau, senior research manager for IDC's Asia/Pacific client device team. "What's changed now is the added pick up of phablets in emerging markets like China and India, not just the plethora of big-name vendors competing head-to-head with Samsung, but instead the low-cost local players who have swooped in to offer big screens for less money – averaging a retail price of US$220 versus Samsung's US$557."

Dell lost out by being too early to the market with the Streak, introducing it at a time when most users had smaller phones with screens under 4in diagonally. But the rise in smartphone penetration, and the shift to more data-centric uses such as maps, has made big screens popular - particularly in countries where the device needs to serve multiple computing needs.